CODEWITHSUNDEEP
linuxshell
Smith
Smith

Reputation: 637

Multiple conditions in if

    [ -r "$df" ] && {   
        tail -1 $df | grep "$was_fallback" > /dev/null     
        [ $? -ne 0 ] && { continue; }

This is part of a larger code. I am reading some old codes written by seniors. And then I found this piece of code. I know that [ ] is for 'if' condition. But what is this {} used for?

Upvotes: 2

Views: 143

Answers (1)

P.P
P.P

Reputation: 121427

I know that [ ] is for 'if' condition

No. It's not the if condition. [ is the test command. More about it here:

What is the difference between test, [ and [[ ?

what is this {} used for?

It's called command grouping. From the GNU manual:

{}

    { list; }

    Placing a list of commands between curly braces causes the list to be
    executed in the current shell context. No subshell is created. 
    The semicolon (or newline) following list is required.

Upvotes: 3

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